I'm considering purchasing a KA Formula 9.8 sail for the largest sail for early planning with iSonic 122 (2007). Does anyone have experience of using such big sails with iSonic 122? I guess a big fin (0ver 50 cm?) would also be required for that combo?
My weight is 76 kg.

Sam , For your weight I think you would be better off with a 9.0 Koncept . The 9.8 Formula is really geared towards upwind /downwind Formula sailing , noticebly heavier and stiffer to sail with . The 08 sail is working great on Formula boards but I also think it is maybe getting too big for the 122 . The 9.0 Koncept is still very powerful and has a much lighter feel . It,s a great sail !!!

Thank you for a quick reply!
How would you compare the low end grunt of Formula 9.8 and Koncept 9.0?
You mentioned that the 9.0 Koncept is also very powerful, so would there be any benefit at all from using the 9.8 in terms of early planning or do I get the same (or) better low end from Koncept 9.0?

Sam , I am not sure that you will notice any great difference with the low end of the 9.0 Koncept with the 9.8 Formula . The Koncept being noticably lighter and a bit softer will be far easier to pump . Where the Formula has the advantage is at the top end where it,s extra battens and cams really lock in the draft and make the sail super stable even when overpowered .
Where are you ? perhaps we can arrange a demo sail ?
Regards Martin

Hi Sam, I have tried a 9.5 Formula sail on the 122 and found it to be just a little
bit too big for the board. You can get the board planning no probs but its really
hard work to keep it going upwind. I even bought a 50cm fin and it didnt help.
I would agree with Martin and definately go with the Koncept, especially with
your weight you wont be dissapointed.

Every board have a best choice-sail, for medium sailor, in spite of "marketing" wide sail-range... The best choice for I-sonic 122 is 7.5-7.8 sail. It's better to use a formula board with a fin near to 60-65 cm, if you need to use a 9.8. It's difficult to control a bigger sail with such a table, specially with "rising" waves.
Giuseppe ITA 50